updated readme

README.md

@@ -0,0 +1,77 @@
+# FixedCal
+
+Python package for international fixed calendar dates.
+
+## What is that?
+
+International fixed calendar is an alternative calendar system. It divides year into 13 even months by adding a month called Sol between June and July. Each month starts with Sunday and has exactly 28 days or 4 weeks. An additional _year day_ is added to the end of the year and it does not belong to any of the months and has no weekday. You can read more about IFC on [Wikipedia](https://en.wikipedia.org/wiki/International_Fixed_Calendar).
+
+## Usage
+
+### Date initialization
+
+```python3
+from fixedcal import FixedDate
+
+# Date of today
+fixed_date = FixedDate.today()
+
+# From native datetime
+from datetime import datetime
+feburary_seventh = datetime(2022, 2, 7)
+fixed_date = FixedDate(feburary_seventh)
+
+# From day's ordinal in year
+fixed_date = FixedDate(day_of_year=107, year=2022)
+```
+
+### Date's properties
+
+```python3
+from fixedcal import FixedDate
+from datetime import datetime
+fixed_date = FixedDate(datetime(2022, 8, 12))
+
+fixed_date.datetime			# datetime(2022, 8, 12, 0, 0, 0)
+fixed_date.day_of_year		# 224
+fixed_date.day_of_month		# 28
+fixed_date.month			# 8
+fixed_date.year				# 2022
+fixed_date.is_year_day		# False
+fixed_date.week_of_month	# 4
+fixed_date.weekday			# 7
+fixed_date.week_of_year		# 32
+fixed_date.year_quarter		# 3
+
+```
+
+### Date's operations
+
+```python3
+from fixedcal import FixedDate
+from datetime import datetime, timedelta
+fixed_date = FixedDate(datetime(2022, 12, 6))
+jan_first = FixedDate(datetime(2023, 1, 1))
+
+new_fixed = fixed_date + timedelta(3)	# FixedDate 3 days ahead
+new_fixed = fixed_date - timedelta(2)	# FixedDate 2 days before
+new_fixed = jan_first - fixed_date		# timedelta between dates
+
+fixed_date == fixed_date				# True
+fixed_date != jan_first					# True
+jan_first < fixed_date					# False
+```
+
+### Year day
+
+Year day is the day after the last of December and before the first of January. For that date, `FixedDate` gives the following property values.
+
+* `day_of_year` = 365
+* `day_of_month` = 1
+* `month` = 14
+* `year` is obviously the ending year
+* `is_year_day` = True
+* `week_of_month` = 1
+* `weekday` = 1
+* `week_of_year` = 53
+* `year_quarter` = 4